Montreal Mayor Denis Coderre says he won't apologize for calling controversial imam Hamza Chaoui an agent of radicalization, and says that if Chaoui acts on his threat of a lawsuit, he will defend himself.

Chaoui's lawyer sent a letter to Coderre, asking him to retract statements he made in public — or face a lawsuit.

Chaoui said he was unjustly accused of being an agent of radicalization by elected city officials and the mayor, and if he doesn't get a public apology from Coderre he'll sue for damages.